The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between ...

Grass cropping in the rotation and the use of no-till seeding appear to be important components for developing sustainable cropping systems. Grass cropping and no-till seeding improve soil organic matter content, increase the soil microbial biomass, increase earthworm numbers, likely cause a buildup of fungivorous microarthropods and nematodes, and greatly increases the resistance of soil to er...

Rice (Oryza sativa L.) is the most important staple food crop in many developing countries, and is ranked third in Kenya after maize and wheat. Continuous cropping without replenishing soil nutrients is a major problem in Kenya resulting to declining soil fertility. The use of chemical fertilizers to avert the problem of low soil fertility is currently limited due to rising costs and environmen...

BACKGROUND Iron (Fe) deficiency in crops is a worldwide agricultural problem. Plants have evolved several strategies to enhance Fe acquisition, but increasing evidence has shown that the intrinsic plant-based strategies alone are insufficient to avoid Fe deficiency in Fe-limited soils. Soil micro-organisms also play a critical role in plant Fe acquisition; however, the mechanisms behind their p...

Recent studies on the speciation of Zn in contaminated soils confirmed the formation of Zn-layered double hydroxide (LDH) and Zn-phyllosilicate phases. However, no information on the kinetics of the formation of those phases under field conditions is currently available. In the present study, the transformation of Zn in a field soil artificially contaminated with ZnO containing filter dust from...

Estimates of numbers of micro-organisms occurring in three differently manured soils, made by a direct-counting and plating technique, were compared. No correlation was found between the two methods and reasons for the large discrepancy between them are discussed. Contradictory information of the effect of external factors on soil micro-organisms can be given by the two different methods of cou...

General Purpose (use of) Graphics Processing Units (GPGPU) is a promising technology for simulation upscaling; in particular for bottom–up modelling approaches seeking to translate micro-scale system processes to macro-scale properties. Many existing simulations of soil ecosystems do not recover the emergent system scale properties and this may be a consequence of “missing” information at finer...

1. Desertification negatively impacts a large proportion of the global human population and > 30% of the terrestrial land surface. Better methods are needed to detect areas that are at risk of desertification and to ameliorate desertified areas. Biological soil crusts are an important soil lichen-moss-microbial community that can be used toward these goals, as (i) bioindicators of desertificati...

Microorganisms are fundamental to biogeochemical processes, as microbial metabolism significantly contributes to the regulation of terrestrial carbon and nitrogen cycling. However, the impact of the community of soil microbes within the mycorrhizosphere has not been examined in detail due to the difficulty of tracking micro-scale processes in natural microbial communities in complex soil habitats.

There is increasing interest among growers in novel establishment systems for cover crops that can rehabilitate and protect soil. Cropping intensification has led to yield declines, compacted and poor quality soil, and increased pest problems. Cover crops in the Brassica (mustard) family offer benefits in soil conservation, improvement in soil quality, reduction in nitrate leaching, and suppres...